Internal combustion engine speed regulators combined with changeable length accelerator linkages have been well-known in the prior art, U.S. patent application Ser. No. 168,566 filed July 14, 1980, and U.S. Pat. No. 4,181,103 being most pertinent, although U.S. Pat. Nos. 2,365,412, 2,742,792, 2,328,452, 3,721,309, 3,923,020, and 4,059,025 also disclose relevant subject matter.
While all the above-mentioned prior art discloses changeable length accelerator linkages which allow one throttle control means to override another, none of them permit normal operation and "feel" of the conventional accelerator pedal when the speed regulator or governor is actively limiting throttle opening; and, conversely, they do not permit the governor to close the throttle from an open position (as determined by operation of the coventional accelerator pedal) without significant "feedback" or alteration of the "feel" or position of the accelerator pedal.
The aforesaid application Ser. No. 168,566 indicates that the accelerator pedal will have a generally "normal feel" just as a conventional accelerator pedal and throttle linkage, but that indication was made in the context of the most pertinent prior art known at that time, principally the aforesaid U.S. Pat. No. 4,181,103. The changeable length accelerator-carburetor-governor linkage of U.S. Pat. No. 4,181,103 operated such that when the governor held the throttle fully closed it also held the accelerator fully depressed, and if the governor operated to lengthen the linkage when the accelerator was fully up and the throttle thereby already closed, then the governor would draw the accelerator pedal down to the floorboard, both being highly unnatural actions so far as the "normal feel" of the accelerator pedal was concerned. Also, since the flexible sheath of the flexible cable portion of this linkage was not anchored at the carburetor end thereof, but was movable with the extending end of the throttle arm, the flexible sheath was flexed laterally with each throttle arm movement and thereby subject to interference with various nearby engine components, causing wear or other problems.
Therefore, the "normal feel" described in the aforesaid application Ser No. 168,566 referred to the fact that the accelerator pedal thereof was not forcibly depressed or "taken away" from the operator when the governor acted to close the throttle, but the accelerator pedal could be positioned as desired but without effect on the throttle position. However, a spring, described as "substantially stronger" than the spring which normally holds the throttle closed, forms the changeable length element of the accelerator-carburetor-governor linkage of application Ser. No. 168,566, and the added force of this "substantially stronger" spring must be resisted by the operator in order to hold an accelerator pedal position in opposition to throttle-closing action by the governor.
The "feel" of such a linkage may be "normal" in the directional sense as compared to the abnormal directional feel of the apparatus of U.S. Pat. No. 4,181,103 or to a common or conventional fixed-length accelerator-throttle linkage, but it is not "normal" in the sense of the substantially stronger force required to depress or hold the accelerator pedal against throttle closing or governing action of the governor as compared to its "normal" operation when the governor is not governing. Also, the forces involved appeared in practice to be dangerously strong for long-term use without damage to the conventional components of the linkage.
The changeable length linkage of the present invention not only provides normal feel in the directional sense as does the application Ser. No. 168,566 (i.e., the accelerator pedal is never "taken away" from the operator), but also in the sense that the force required to depress or hold the accelerator against throttle-closing governing action by the governor will be only slightly stronger than the force required when the governor is not governing. Thus, the operation, or operational feel, of the accelerator pedal of the present invention is not significantly affected, either as to the direction of motion or the force required, by the operation of the governor, thereby providing a significantly advantageous and saleable feature for a changeable length accelerator-carburetor-governor linkage.